Feeder protection measurement and control device REF545KB133AAAA

The functionality available for REF 54_ depends on the selected functionality level

(refer to Section “Ordering Information” on page 103) and is also tied to the

hardware configuration. The desired functions can be activated from a wide range

of protection, control, measurement, power quality, condition monitoring, general

and communication functions within the scope of I/O connections, considering the

total CPU load. Compared to the traditional use of separate products, the

combination of desired functions provides cost-effective solutions and, together

with the relay configuration (IEC 61131-3 standard), allows the REF 54_ feeder

terminals to be easily adapted to different kinds of applications.

By means of the graphic HMI display, the control functions in the feeder terminal

indicate the position of disconnectors or circuit breakers locally. Further, the feeder

terminal allows position information from the circuit breakers and the disconnectors

to be transmitted to the remote control system. Controllable objects, such as CBs, can be opened and closed over the remote control system. Position information and

control signals are transmitted over the serial bus. Local control is also possible via

the push-buttons on the front panel of the feeder terminal.

The feeder terminal is designed to be used for the selective short-circuit and earthfault protection. The feeder protection type REF 54_ includes overcurrent and earthfault functions and is used for feeder short-circuit, time overcurrent and earth-fault

protection in solidly, resistant or resonant-earthed networks and in isolated neutral

networks. When desired, auto-reclosing is achieved by using the auto-reclose

function. Up to five successive auto-reclose cycles can be carried out. For an

example application with basic functions, see Fig. 4.1.-2 below.